Python type hints are used ahead of time, by the type-checking system; for instance, in your editor or IDE. In other words, Python’s type hints are for the developer, not the runtime.

To invoke a specific edition of Python, type py followed by the switch in the left-hand column for the appropriate version. For instance, to launch the 64-bit edition of Python 3.9, you would type ...

Learn how Mypy's type checking works with functions and generators. In my last two articles I've described some of the ways Mypy, a type checker for Python, can help identify potential problems with ...